Aerospace designers must balance several factors in the design of structures and components. Designers appreciate the complex interplay between weight, strength, costs, material properties, environmental conditions and the multitude of service requirements for various components. First, aircraft components must be lightweight to ensure fuel economy, but strong enough to meet structural and performance requirements. Hence, composite structures often are selected due to their sturdiness and low weight densities. Second, the environment in which these structures operate also requires erosion resistance, as aerospace structures are exposed to impact by rain, sand, ice, hail and other foreign objects. These objects can degrade surface finish and create abrasion, which can result in high drag coefficients, which contributes to reduced fuel economy for the aircraft on which they are used. Third, the changes in altitude and temperature differentials during operation of an aircraft subject the aircraft's components to extreme thermal cycling that can cause microcracking. Fourth, long term exposure to sunlight and ultraviolet (UV) radiation can degrade the properties of aircraft components. Finally, the possibility of lightning strikes requires consideration of the electrical conductivity of external components. In order to meet performance requirements and extend performance life, designers must properly plan for and design structures and materials to function under these varied conditions.
Coatings and/or film laminates are often applied to the external surface of aerospace structures to assist in meeting the component's operational requirements. However, many of the commercially available films and coatings often exhibit acceptable properties for one design factor at the expense of one or more other factors. For example, a newly designed film may provide superior erosion resistance but at the expense of degraded UV resistance and/or lightning strike protection.
There is a need, therefore, for an improved film and laminate for use in aerospace applications that optimally addresses the multitude of needs imposed by operational and environmental conditions. Examples of aerospace structural components that can benefit from improved film and laminates include wings, fuselage, tails, nacelles, rotary blades, as well as other component parts.